Two endosymbionts, Chaetosalpinx sibiriensis and Coralloconchus bragensis, occur in Silurian tabulate corals of Podolia. The endosymbiotic worms responsible for C. sibiriensis bioclaustrations in tabulates are found only in certain species: Paleofavosites cf. collatatus, Heliolites sp. A, Heliolites sp. B, Heliolites sp. C, Favosites gothlandicus, Favosites sp. A. One to six C. sibiriensis-infested tabulate species are known from Late Homerian to Ludfordian, in the reef-related community. Chaetosalpinx sibiriensis preferred certain tabulate species over the others, but showed no preference for the favositid or heliolitid type of morphology.